KR0152801B1 - Image signal processing circuit for multi-screen - Google Patents

Abstract

The present invention provides a multi-screen processing circuit for digitally processing and compressing an image signal at the level of a composite color signal without compressing the image signal at the level of a luminance signal or a color difference signal to simplify the circuit configuration. After performing low pass filtering and A / D conversion of (CV _main ), the _main image video signal compression unit 100 compresses the desired direction in the horizontal / vertical direction and stores it in the memory, and the composite color signal (CV _sub ) for the sub picture. After the low-pass filtering and A / D conversion of the sub-screen video signal compression unit 200 for storing in the memory in the desired direction of the horizontal / vertical direction, and the video signal compression unit 100 for the main and sub-screen, Averaging and Y / C separation unit 300 for synthesizing the composite color data (Y + C) for the main / sub picture, which is read and input from the memory of 200, and then averaging and filtering in a desired direction in the vertical and horizontal directions. And, the averaging and Y / C separation unit 30 After receiving color gradation data from 0) and performing color demodulation, D / A conversion and low-pass filtering output restored color difference signals (RY) and (BY), and luminance data is restored by D / A conversion and low-pass filtering. And a timing control signal ( _{m1CLK, m2} ) respectively supplied with the video signal output unit 400 for outputting the luminance signal Y, and the main color composite color signal CV _main and the sub color composite color signal CV _sub . ) And the timing control signal generator 500 for the main screen and the timing control signal generator 600 for the sub-screen which generate the timing control signals S _{1 to} S ₅ , respectively. It was.

Description

Image signal processing circuit for multi screen

1 is a block diagram of a general digital video signal processor.

2 is a block diagram of a multi-screen circuit of a general video signal processor.

3 is a video signal processing block diagram for a multi-screen of the present invention.

4 is a detailed block diagram of one embodiment of a compressor in FIG.

(A) and (b) of FIG. 5 are input and output waveform diagrams of the compressor at double compression using ˜m ₂ / s ₂ in FIG. 4.

6A to 6K are output timing diagrams of the timing control signal generator in FIG.

7 is a block diagram of an exemplary embodiment of a timing control signal generator in FIG.

(A) to (c) of FIG. 8 are exemplary views of a compressed screen according to the present invention, (a) is a screen configuration diagram when the video signal is compressed 1/2 in the horizontal direction, and (c) is a video signal. Fig. 1 shows the screen configuration when the image is compressed 1/2 in the vertical direction, and (a) shows the picture configuration when the image signal is compressed 1/2 in the horizontal and vertical directions.

9 is an exemplary block diagram of a vertical averaging and Y / C separation filter in accordance with the present invention.

FIG. 10 is a block diagram of one embodiment of the filter when using only the horizontal averaging and Y / C separation filters without using the vertical averaging and Y / C separation filters.

FIG. 11 is a block diagram of an embodiment of a horizontal averaging for a Y / C signal and a Y / C separation filter when each half is compressed in the horizontal / vertical direction.

12 is a block diagram of one embodiment of a filter when half compressed only in the horizontal direction.

(A) of FIG. 13 is a waveform diagram showing the transfer characteristics of the vertical averaging and Y / C separation filters used for luminance separation, and (b) shows the transfer characteristics of the vertical averaging and Y / C separation filters used for color separation. Waveform diagram.

14 is a waveform diagram illustrating the principle of a color decoder.

FIG. 15A is an explanatory diagram showing a modulation principle of a digital color signal applied to the present invention, and (b) is an explanatory diagram showing a demodulation principle of a digital color signal applied to the present invention.

FIG. 16 is an exemplary circuit diagram of a color decoder in FIG.

* Explanation of symbols for main parts of the drawings

100: video signal compression unit 101,201,403-407 for the main screen: low pass filter

102,202: A / D converter 103,203: compressor

104,204: Memory 200: Video signal compression unit for sub picture

300: averaging and Y / C separation unit 301: synthesizer

302 Vertical averaging and Y / C separator 303 Horizontal averaging and Y / C separator

400: video signal output unit 401: color decoder

402,404,406: D / A converter 500: Timing control signal generator for main screen

501,601: Synchronous separator 502,602: Clock generator

503: timing control signal generator for the main screen 600: timing control signal generator for the sub-screen

603: timing control signal generator for sub picture

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for compressing and synthesizing an image signal, and in particular, an image signal processor for digitally processing and compressing an image signal at a level of a composite color signal without compressing the image signal at a level of a luminance signal or a color difference signal for simplifying a circuit configuration. The present invention relates to a video signal processing circuit for a multi-screen which can be applied to the multi-screen processing circuit.

FIG. 1 is a block diagram of a general digital video signal processor, and FIG. 2 is a multi-screen processing block diagram of a general video signal processor. As shown in FIG. 1, a luminance signal Y is supplied by receiving a composite color signal CV _main for a main screen. ) And a color generating the color difference signals RY and BY by receiving the Y / C separator 11 separating the color signal C and the color signal C output from the Y / C separator 11. A decoder 12, an A / D converter 13 for converting the separated analog luminance signal Y into a digital signal, a luminance signal compressor 16 for compressing the output signal thereof as necessary, and the analog An A / D converter 14 for converting the color difference signal RY into a digital signal, a color difference signal compressor 17 for compressing the output signal thereof if necessary, and the analog color difference signal BY as a digital signal. An A / D converter 15 for converting and compressing the color signal, and a color difference signal compression unit 18 for compressing the output signal thereof if necessary, A luminance signal Y, a color difference signal C _R , and a C _B , respectively converted into a digital signal (compressed through a compression path, if necessary) is supplied and multiplexed to increase the efficiency of the memory 20. The multiplexer 19 stored in the memory 20 and the sub-picture composite color signal CV _sub are compressed in the same way as in the process of processing the main screen composite color signal CV _main during multi-screen processing. ) Y / C separator 21, color decoder 22, A / D converter 23 and luminance unit 23 of luminance signal, A / D converter 24 of color difference signal RY And the compression unit 26, the A / D conversion unit 25 and the compression unit 28 of the color difference signal BY, the multiplexer 29, and the memory 20 and 30 in a compressed form. A synthesizer 31, a demultiplexer 32, for outputting the combined color signal for the main picture and the combined color signal for the sub picture as an original luminance signal Y, color difference signal RY, and BY through one channel. D / A conversion and filtering unit (33), (34 ) And 35, and a timing control signal generator 40 for supplying timing control signals to the respective systems and controlling their operation. The operation thereof will be described as follows.

The main color composite color signal CV _main is separated from the luminance signal Y and the color signal C through the Y / C separator 11, and the separated color signal C is predetermined through the color decoder 12. Are converted into color difference signals RY and BY having an amplitude of.

The separated luminance signal Y and the color difference signals RY and BY are converted into digital signals through the respective A / D converters 13, 14, and 15, and the luminance signal Y In the following example, the digital conversion process is performed by first performing a low pass filtering through an antialiasing filter 13A to prevent sampling noise, and then again using an analog (A) / digital (D) converter 13B. Convert to a signal.

When composing a multi-screen or PIP screen, the image is compressed. The compression of the image implies the loss of pixel information of the uncompressed image. The interpolation value in the vertical and horizontal directions is taken through the group 16B, and then compressed through the compressor 16C.

After the luminance signal Y, the color difference signal RY, and BY are output as the digitally converted luminance signal Y, the color difference signal C _R , and C _B through the above process, the memory ( In order to increase the efficiency of 20, the multiplexer 19 stores the multiplexer 19 in the memory 20.

Meanwhile, in the multi-screen configuration, the sub-screen composite color signal CV _sub is stored in the memory 30 through the same process as that of the main screen composite color signal CV _main .

In the case where only one main screen is digitally processed, the sub-screen unit and the compression units 16, 17, and 18 are excluded from the multi-screen configuration, and only the multi-screen configuration will be described below.

Data of the luminance signal (Y) and the color difference signal (CR), (C _B ) of the main and subchannels respectively stored in the memory (20), (30) are read of the memory (20), (30). According to the method, it is synthesized on one channel (multi-screen configuration). In particular, when data of the memory 30 of the sub-screen channel is written, it is made by a clock signal in which PLL is applied to the composite-color signal for the sub-screen. At the time of reading, data stored in the memory 30 is outputted by a clock signal in which PL is applied to the main picture composite color signal.

The luminance signals (Y) and the color difference signals (C _R ) and (C _B ) data for the main and sub-screens respectively stored in the memories 20 and 30 are synthesized by the synthesizer 31 and the demultiplexer 32. The signal is reduced, and finally converted into an analog signal through the D / A conversion and filtering units 33, 34, and 35, and then low-pass filtered to obtain an analog luminance signal Y, a color difference signal RY, (BY) is output.

For reference, the main channel and the sub-channel are respectively configured as described above, and the main screen luminance signal Y, the color difference signal RY, (BY) and the sub-screen luminance signal Y and The main reason for processing the color difference signals RY and BY is that the color signals cannot be demodulated by the normal decoding method after compression at the color signal (color signal) or the composite color signal level.

As described above, in the conventional multi-screen processing apparatus, the color signal through the color decoder must be continuously restored when the image is compressed, so that the color demodulation cannot be performed after the composite color signal itself is compressed and digitally processed. Therefore, after the color signal is demodulated before compression, the luminance signal and the color difference signal are digitally processed, compressed and synthesized to complicate the configuration, thereby increasing the cost.

Accordingly, an object of the present invention is to provide a video signal processing circuit for multi-screen which digitally processes and compresses the image signal at the level of the composite color signal without compressing the image signal at the level of the luminance signal or the color difference signal to simplify the circuit configuration. have.

The present invention is an exemplary illustrative block diagram of a video signal processing circuit for a display as shown in Fig Thus, the main screen, the composite color signal (CV _main) low-pass filtering for to achieve the object of turning 3 and an A / After low-pass filtering and A / D conversion of the main picture video signal compression unit 100 and the sub picture composite color signal (CV _sub ), which are compressed and stored in a memory in a desired direction after the D conversion. The video signal compression unit 200 for sub-screens, which are compressed in a desired direction among the horizontal / vertical directions and stored in a memory, and are read and input from the memories of the video signal compression units 100 and 200 for the main and sub-screens, respectively. Averaging and Y / C separation unit 300 for averaging and filtering in the desired direction from the vertical and horizontal directions after synthesizing the composite color data (Y + C) for the main / sub picture, and the averaging and Y / C separation unit Color demodulation processing from progressive color difference data from 300 Then, the video signal output unit outputs the restored color difference signals RY and (BY) by D / A conversion and low pass filtering, and outputs the restored luminance signal Y by D / A conversion and low pass filtering. And a timing control signal m _1- m ₅ and a timing control signal S _1- S ₅ respectively supplied with the _main color composite color signal CV _main and the sub picture composite color signal CV _sub . And a main screen timing control signal generator 500 and a sub-screen timing control signal generator 600 which respectively generate the subfields, respectively. A detailed description with reference to FIG. 16 is as follows. For reference, in FIG. 3, only the sub picture processing unit 201, 202, 203, and 204 may be excluded in the digital processing of the main picture. 103).

First, the process of compressing the main picture composite color signal CV _main by the main picture video signal compression unit 100 will be described. A low pass of the _main picture composite color signal CV _main is performed to prevent sampling noise. After the low pass filtering through the filter 101, the A / D converter 102 converts the digital signal into a digital signal, and then, by the compressor 103, 1/2 ^N (N = 1, 2, 3...) In the horizontal or vertical direction. Compression or 1/2 ^N compression in the horizontal and vertical directions, respectively. First, the compression of 1/2 in the horizontal and vertical directions will be described as an example. The compressor 103 is flip-flop (eg, DF) as shown in FIG. / F) and can be compressed 1/2 in the horizontal or vertical direction as shown in FIG. 5 by using the timing control signal m ₂ as shown in FIG. The compressed video signal is stored in the memory 104. At this time, the amount of memory can be reduced by the compressed ratio.

The present invention can be applied to the compression of 1/2 ^N (N = 1,2,3…), and means only digital processing without compressing the image as 1/2 ^N = 1 when N = 0. do. Since 1/2 ^N is an expansion concept of 1/2 times, mainly the compression of 1/2 times will be explained.

On the other hand, the sub-screen composite color signal (CV _sub ) is the main screen composite color signal (CV _main ) through the sub-screen video signal compression unit 200 configured in the same way as the main screen video signal compression unit 100 ) Is stored in the memory 204.

However, a memory 104 corresponding to a frame / compression rate should be used for the video signal processing channel of the sub picture to synchronize horizontally and vertically with the main picture. The type of 104 may vary. In other words, if you compress half only in the horizontal direction, you only need to use the line (H) / 2 size memory.

When 1/2 compression is performed in the horizontal direction, multiple screens are synthesized by timing control of the memory 104 and 204 used to compress and synchronize an image. When writing, the memory 104, 204 is supplied with two divided timing control signals (m ₂ / s _2, i.e., when m = 1 at m ₂ / s ₂ ^N ) as shown in FIG. 6C. The timing control signal mE _N / sE _{N as} shown in FIG. When the memories 104 and 204 are read, the timing control signal m _CLK / s _CLK is supplied as shown in FIG. _6B which is twice as fast as when the write is performed. The signal m _{REN as} shown in FIG. _6F is supplied as the lead enable signal of the main screen, and the signal as shown in FIG. 6G as the lead enable signal of the sub-screen memory. That is, the read timing is twice as fast as the write timings of the memories 104 and 204.

If you compress at an arbitrary 2 ^N times (e.g. 2 times, 4 times, 8 times, ……, 2 ^N-1 , 2 ^N ), you can apply a 1/2 ^N divided light clock signal ( _m2 ^N / _s2 ^N ). In this case, the principle of color demodulation will be described later.

For reference, in generating a timing control signal using a clock signal generated by the PLL circuit as shown in FIG. 7, the symbol display of the timing control signal is based on a clock generated by the PLL being applied to the horizontal synchronization signal of the main screen. One timing control signal is denoted by m _x , and the timing control signal locked to the horizontal synchronization signal of the sub-screen image signal is denoted by s _y . Where x and y are arbitrary integers.

In the present invention, it is possible to compress arbitrarily with respect to the horizontal / vertical direction, but when 1/2 compression only in the horizontal direction, the screen is displayed as shown in (a) of FIG. 8, and when 1/2 compression only in the vertical direction This is displayed as shown in (b) of FIG. 8, and the screen is displayed as shown in (c) of FIG. 8 when it is compressed 1/2 in both the vertical and horizontal directions.

The composite color data for the main / sub picture, respectively read from the memory 104 and 204, is synthesized through the synthesizer 301 and then horizontally averaged and Y / C separated from the vertical averaging and Y / C separation filters 302. Only one or both of the filters 303 may be used to filter in only one of the horizontal and vertical directions, or to filter in two directions, each of which is illustrated in FIGS. 9 to 12. At this time, the characteristics of each filter are as follows.

First, looking at the characteristics of the vertical filter applied to the vertical averaging and the Y / C separation filter 302,

Expressed in terms of its frequency response

Its transmission characteristic curve is shown in (a) of FIG.

And, if the transmission characteristic of the color signal is found in the same way,

Its transmission characteristic curve is shown in Figure 13 (b).

Be seen that at least as shown in the illustration, the horizontal frequency (f _H) of a color signal (C) which is located on an odd multiple of the luminance signal (Y) and a horizontal frequency (f _H) that is located in an even multiple comb filter that completely separate the have.

Referring to the vertical averaging and the Y / C separation filtering characteristics of the Y / C separation filter 302 configured as shown in FIG. 9, since the color signals of the current line and the front and back lines have a phase inversion relationship, the current line signal Is represented by Y + C, and the front and rear line signals are represented by YC, by using the same principle, averaging of two lines and Y / C separation is described as follows.

The signal Y + C of the current line output from the memory 104 or the memory 204 is attenuated at half level through the 1/2 amplifier 311 and outputted. And a horizontal line delayed through the line memory 312 so that the color signal C is inverted, that is, YC, as described in the above description, which is again output through the 1/2 amplifier 313. As above Is output. The output signals of the amplifiers 311 and 312 are added by the synthesizer 314 to output a pure luminance signal Y = Yv from which color signals are removed, which is supplied to another synthesizer 315 to supply the memory. (104) or the signal Y + C of the current line output from the memory 204, i.e., Y-Y + C = C, so that the synthesizer 315 has a pure color signal (C = Cv) from which the luminance component has been removed. Is output.

On the other hand, in the case of using only the horizontal averaging and Y / C separation filter 303 without using the vertical averaging and Y / C separation filter 302 is shown in Figure 10, the horizontal averaging and Y / Since the C-separated filtering characteristic is almost the same as the horizontal averaging and the Y / C-separated filter 302, a separate description is omitted.

In addition, when filtering in the vertical and horizontal directions using both the vertical averaging and the Y / C separation filter 302 or the horizontal averaging and the Y / C separation filter 303, the horizontal averaging and the Y / C separation filter 303 The operation is as follows.

The luminance signal Yv output from the vertical averaging and the Y / C separation filter 302 is delayed by one line through the delay unit 331, and then amplified to 1/2 level through the half amplifier 332. The luminance signal Yv is amplified to one half level through a half amplifier 333 on the other hand and provided to the other input of the synthesizer 334. Accordingly, the synthesizer 334 generates the luminance signal Y by adding the luminance signal input with the parallax of one line through the above path.

In addition, the color signal Cv output from the vertical averaging and the Y / C separation filter 302 is transmitted through the retarder 335, the 1/2 amplifier 336, 337, and the synthesizer 338. Yv), and a color signal Cv is output from the synthesizer 338.

In addition, FIG. 12 shows an example of using a comb filter to compress the video signal 1/2 in the horizontal direction but improve the Y / C separation characteristics. The difference from FIG. 11 will be described below.

This is to prevent the color signal from changing to the state of the luminance signal (Y) when the primary color signal of the red, green, and blue signals (R, G, B) is restored by the relational equation. However, when ignoring the deterioration of the image quality, the horizontal averaging and the Y / C separation filter 303 having the configuration shown in FIG. 11 may be used.

Meanwhile, a new decoder, that is, a color decoder, is required to compress and digitally process a video signal at a composite video level. The principle of the color decoder 401 applied to the present invention will be described with reference to FIG.

When the color demodulation of and an arbitrary clock is used, the Fourier Series is represented by the following equation.

Where n = 0, +1, -1

You can get the function of.

Here, the constant value (magnitude of amplitude) is meaningless.

As can be seen from the above equation, in the digital mode, as shown in FIG. The signal is selectively received to generate C [n], and during demodulation, as shown in FIG. 15 (b), the switching of the switch 421 is controlled by the color carrier signal 4fsc to selectively receive the C [n]. By controlling the switching of the switches 423 and 425 with the color subcarrier signal 4fsc / ^2N , the color difference signals C _R and C _B can be modulated.

Therefore, the timing control signals m ₂ ^N and (s ₂ ^N ) are respectively supplied to the compressors 103 and 203 to compress the video signals, that is, only the color difference signals C _R and C _B are stored in the memory 104, The color difference data, which is stored in 204 and is not stored in the color difference signals -C _R and -C _B, is read at a clock speed of 2 ^N times as in writing, so that the color difference data C _R1? C _B2? C _R2? C _B2 Color decoder which is output in sequential data form and consists of compressors 1,2 (501) and 502 (e.g. D flip-flop) and the clock signal m _CLKR (m _CLKB ) of FIG. Color demodulation may be implemented using 401.

In addition, the color demodulated signals C _R , C _B , and luminance signal Y as described above are converted into analog signals through the D / A converters 402, 404, and 406, respectively. Color filter signals RY, BY, and luminance signal Y, which are low-pass filtered and reconstructed through the low-pass filters 403, 405, and 407, are output.

Meanwhile, referring to the operation of the main screen timing control signal generator 500, the main color composite color signal CV _main is separated from the synchronizing signal through the synchronizing separator 501, and the clock generator 502 The clock signal is generated using the separated synchronization signal, and the timing control signal generator 503 for the main screen supplies the timing control signals _m1-m5 to the respective parts by using the clock signal. In addition, the sub-screen timing control signal generator 600 receives the composite color signal CV _sub for the _sub- screen and processes it in the same way as the timing control signal generator 500 for the main screen, whereby the timing control signal ( _s1-s5 ).

As described in detail above, the present invention does not compress the image signal at the level of the luminance signal or the chrominance signal, but digitally processes and compresses at the level of the composite color signal, thereby simplifying the circuit configuration and contributing to the miniaturization of the product. There is a saving effect.

Claims (6)

Low-frequency filtering and A / D conversion of the main picture composite color signal (CV _main ) and the video signal compression unit 100 for the main picture, which is compressed in a desired direction among horizontal and vertical directions and stored in a memory, and the sub picture synthesis After _sub -filtering and A / D conversion of the color signal (CV _sub ), the sub picture video signal compression unit 200 compresses the desired direction in the horizontal / vertical direction and stores it in a memory, and the main and sub picture video signals. Averaging and Y / A for synthesizing the composite color data (Y + C) for the main / sub picture which is read and input from the memory of the compression unit 100 and 200, respectively, and averaging and filtering in a desired direction among the vertical and horizontal directions. Color difference signal RY, which is restored by D / A conversion and low-pass filtering after color demodulation processing by receiving progressive color difference data from the C separation unit 300 and the averaging and Y / C separation unit 300. ), And output the restored luminance signal (Y) by D / A conversion and low-pass filtering the luminance data. A video signal output section 400, a main composite color signal for display (CV _main) and a sub-timing control signal to a composite color signal (CV _sub) received respectively supplied for display _{(m1CLK, m2)} and the timing control signal (S ₁ to -S ₅ ) a video signal processing circuit for a multi-screen, characterized in that the main screen timing control signal generation unit 500 and the sub-screen timing control signal generator 600 for generating each. 2. The timing control signal of 2 ^N according to claim 1, wherein when the data compressed at 1/2 times in the main and sub picture video signal compression units 100 and 200 are respectively stored in the memory, the 2 ^N divided timing control signals _{m 2} ^N / s ₂ ^N And a timing control signal ( _mCLK / _sCLK ) which is 2 ^N times faster than at the time of read, when used for _reading . The method of claim 1, wherein the averaging and Y / C separation unit 300 synthesizes the composite color data for the main / sub picture, respectively read from the memories of the video signal compression units 100 and 200 for the main and sub picture. Vertical averaging and Y / C separation filter 302, horizontal averaging for filtering in only one of the vertical and horizontal directions or filtering in two directions by receiving the synthesizer 301 and the output data of the synthesizer 301 And a Y / C separation filter (303). 4. The filter according to claim 3, wherein when using either the vertical averaging and the Y / C separation filter 302 or the horizontal averaging and the Y / C separation filter 303, the averaging and separation filter is outputted from the synthesizer 301. First amplifying means for amplifying the composite video signal Y + C of the line 1/2 and delay means for delaying and outputting the composite video signal Y + C of the current line output from the synthesizer 301 by one line; And a second amplifying means for amplifying the composite video signal Y + C output from the delay means by 1/2, and a synthesized video signal output from the first and second amplifying means, respectively, to obtain a luminance signal Y. A color signal C by subtracting an output luminance signal Y of the first synthesis means from a first synthesis means for generating a first and a synthesized video signal and a synthesized video signal Y + C of the current line output from the synthesizer 301. And a second synthesizing means for generating a video signal processing circuit. 4. The horizontal averaging and Y / C separation filters according to claim 3, when filtering in the vertical and horizontal directions using both the vertical averaging and the Y / C separation filter 302 or the horizontal averaging and the Y / C separation filter 303. 303 denotes a delay unit 331 for delaying the vertical averaging and the luminance signal Y _V output from the Y / C separation filter 302 by one line and outputting the output luminance signal of the delay unit 331. 1/2 amplifier 332 which amplifies 1/2, 1/2 amplifier 333 which amplifies the luminance signal Y _V 1/2, and outputs of the 1/2 amplifiers 332 and 333. and the combiner 334 adds the luminance signal for generating a luminance signal (Y), the retarder (335 to the vertical averaging and Y / C separation filter 302, the color signal (C _V) to the one line delay output which is output from the ), A 1/2 amplifier 336 that amplifies the output color signal of the delayer 335 1/2, a 1/2 amplifier 337 that amplifies the color signal C _V 1/2, and 1 The color signal C is added by adding the output color signals of the / 2 amplifiers 336 and 337. A video signal processing circuit for a multi-screen, characterized in that consisting of a synthesizer (338) for generating. Low-frequency filtering and A / D conversion of the main picture composite color signal (CV _main ) and the video signal compression unit 100 for the main picture, which is compressed in a desired direction among horizontal and vertical directions and stored in a memory, and the sub picture synthesis Low-frequency filtering and A / D conversion of color signal (CV _sub ) and _sub -image video signal compression unit 200 for compressing to desired direction among horizontal / vertical directions and storing them in memory to save memory when configuring 1 screen In the video signal processor for compressing the _m2 ^N / _S2 ^N clock signal at the composite video signal level, the video signal output unit 400 receives the color difference sequential data C [n], and the predetermined timing control signal ( _mCLKR ) receives the compressor 1 501 which outputs the color difference data C _R [n] in synchronization with the color difference data C [n], and synchronizes the color difference data C _B in synchronization with a predetermined timing control signal _mCLKR . Color deco consisting of compressor 2 (502) output as [n] The video signal processing circuit for a multi-screen, characterized in that further comprises a 401.